Metallurgical furnace construction



'Dec, 30, 1969 w. FADLER METALLURGICAL FURNACE CONSTRUCTION 3 Sheets-Sheet 1 Filed Feb. 16, 1967 VA LTE 7 JFEE R ATTORNEY D ec. 30, 1969 4 FADLER 3,486,745

' METALLURGICAL FUR ACE CONSTRUCTION FiledFeb. 16. 1957 3 Sheets-Sheet 2 FIG-7.2

INVENTOR VHLTER. FRDLER ATTORNEY S w. FADLER METALLURGICAL FURNACE CONSTRUCTION Dec. 30, 1969 3 Sheets-Sheet 5 Filed Feb. 16,. 1967 INVENTOR wau' re mm. WM 51w ATTORNEYEI United States Patent Ofiice 3,486,745 Patented Dec. 30, 1969 METALLURGICAL FURNACE CONSTRUCTION Walter Fadler, Vienna, Austria, assiguor to Wiener Schwachslromwerke Gesellschaft m.b.H., Vienna,

Austria.

Filed Feb. 16, 1967, Ser. No. 616,654 Claims priority, application Austria, Feb. 25, 1966, A 1,776/66 Int. Cl. F27b 14/02, 14/12 US. Cl. 266-33 Claims ABSTRACT OF THE DISCLOSURE SUMMARY OF THE INVENTION This invention relates, in general, to the construction of metallurgical furnaces and, in particular, to a new and useful induction crucible furnace which is supported adjacent each end for pivotal tilting movement for pouring lip at one end and for pouring slag material out over a gutter formation at its opposite end.

In the operation of induction crucible furnaces having a capacity of more than four tons, it is usual to produce a considerable amount of slag. Because of the large size of such furnaces, it is diflicult to skim the slag from the surface of the bath. In most installations, scoops are used for this operation. A disadvantage of such an arrangement is that the operators are exposed to strong radiant heat. It has been proposed to remove the slag through the pouring lip of the crucible but such a step will cause contamination of the lip with the slag which may become detached or entrained in the lip when it is removed in this manner.

In accordance with the present invention, there is provided an induction furnace which includes means for pivotally mounting a crucible such that it may be tilted upwardly to pour material out through its pouring lip at one end or tilted in an opposite direction to pour material outwardly over a gutter to a slag ladle at its opposite end. In this way, the slag can be moved in a simple manner without exposing the operators to dangerous heat. A feature of the construction of the crucible is that it is provided with a gutter or runway for decanting the slag material, and includes means for supporting a slag ladle in a position to readily receive the slag when the crucible is tilted to pour the slag over the gutter.

In one embodiment, the crucible is preferably provided with a covering which is adapted to be tilted about a first pivot together with the crucible. The crucible is preferably tiltable without the cover about the second pivot arranged at the opposite end thereof.

In order to facilitate the tiltable mounting of the cmcible, the supporting stand includes upright open topped forked bearings which are adapted to receive pivots or shafts of the crucible. Means are associated with each fork bearing to close the upper end of the bearing to prevent withdrawal of the pivot members when the crucible is being pivoted about the closed bearing and to permit the upward removal of the pivot members from the bearings with the adjacent end of the crucible when the crucible is to be pivoted about the opposite bearing.

Accordingly, it is an object of this invention to provide an improved induction furnace having means for supporting the crucible so that it may be selectively pivoted about either end for the purpose of pouring the melt or for decanting the slag in accordance with which end is tilted.

A further object of the invention is to provide an induction furnace which includes a mounting stand for a crucible with open-topped fork-shaped bearings which are adapted to receive pivot elements arranged on a crucible adjacent a pouring lip end and at an end having a slag runofi or gutter, with means associated with the pivot bearings for closing the upper end of the bearing when the crucible is at rest, or when it is being pivoted about the associated bearing, and for opening the bearing in order to facilitate pivoting about the bearing located at the opposite end.

A further object of the invention is to provide an induction furnace which is mounted in association with a slag ladle and provided with a gutter formation at one end to permit the decanting of the slag into the ladle and which further includes platform means defined above the furnace which may be pivoted out of the way of the crucible in order to facilitate deslagging from one end or the pouring of the melt from the opposite end of the crucible.

A further object of the invention is to provide a metallurgical furnace which is simple in design, rugged in construction and economical to manufacture.

The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which there are illustrated and described preferred embodiments of the invention.

In the drawings:

FIG. 1 is a side elevational view partly in section of an induction furnace constructed in accordance with the invention.

FIG. 1a is a side elevational section of a part of the furnace indicated in FIG. 1 in an end position of the crucible;

FIG. 2 is a top plan view of the furnace indicated in FIG. 1; and

FIG. 3 is a view smiliar to FIG. 1 of another embodiment of the invention.

Referring to the drawings, in particular, the invention embodied therein comprises an induction furnace construction which includes a mounting stand including end pedestals 40, 40 and 42, 42 arranged at each side and end of the induction crucible generally designated 2. The crucible 2 is supported between two sets of pedestals at each end with only two being visible in the drawings.

In accordance with the invention, the crucible 2 includes a pouring lip formation 3 at one end and a gutter or runway 11 defined at its opposite end for facilitating the pouring off of the slag material. A feature of the construction is that the crucible 2 is mounted for pivotal movement around the axis of pivot members or trunnions 4 which are located adjacent the pouring lip end and also for pivotal movement about the axis of rotation of pivot members or trunnions 17 located adjacent the slag runoff end.

The mounting stand members 40 and 42 include opentopped bearing support portions 19 and 20 with forked upper ends forming a substantially vertically opened recess for receiving pivot members or shaft elements 4 and 17 carried at the pouring end and the slag runoff end of the crucible 2, respectively. The angle through which the crucible is tilted will depend upon the amount of melt 1 Within the crucible. The end position when the melt is to be poured through the lip 3 is indicated to the lefthand portion of the drawings of FIG. 1 in dotted lines.

The crucible 2 is closed by a lid 6, which may be pivoted to one side about a vertical axis 5. The inner wall of the crucible 2 is surrounded by an induction coil 7 and the entire furnace is provided with a covering of sheet metal elements 9, 10 which rest on a carrying frame 8 and which can be swung outwardly to open the area above the crucible. The carrying frame 8 and the crucible are connected in such a manner that the frame 8 and the crucible 2 can be jointly tilted about the pivots 4 and 17. During this tilting movement, the sheet metal elements are automatically locked by means (not shown) so that the sheet metal elements will not tilt forward after a tilting movement beyond 90, such as in the position indicated in dotted lines to the end of the drawing.

A slag bucket 14 is pivotally suspended from the lower ends of mounting arms 12 and 13 which extend around each side of the bucket and are curved in the form of a hook at the lower end which engages around trunnions or pivot members 14a defined on each side of the bucket. The support members 12 and 13 have lower curved hook portions so that the bucket may be freely pivoted therein and also removed when desired. The center of gravity of bucket 14 is such that it will be held upright in the normal operating positions. As shown in FIG. 1, the bucket is positioned so that a front opening 14b is located to align with the gutter 11 so that the slag material may be easily directed along the gutter into the ladle 14. A cover 15 is pivotally mounted at 16 on the frame 8 above the bucket 14 and it may be pivoted rearwardly about the axis 16 to open the top of the bucket if desired. When the crucible 2 is tilted about the axis of the pivot 4, the bucket 14 will pivot in its supporting arms 12 and 13 so that the material in the bucket will not be discharged during this operation.

In order to remove slag from the melt, the crucible 2 is pivoted upwardly about the pivot 17 after first unlatching the pivot 4 by removing a member 21 from engagement around the pivot and covering the forked ends of the support 19. Any slag which is on the surface of the bath 1 will flow through the decanting gutter 11 into the slag bucket 14 through the opening 14b. The angle of the tilting movement for the slag depends on the amount of the melt which is in the crucible 2. The end position of the crucible 2 is indicated in FIG. 1a. During the tilting movement of the crucible 2 about the pivot 17, the slag bucket 14 will remain in the upright position indicated in the drawings for receiving the slag during all positions of tilting movement of the crucible.

Means are provided for tilting the crucible 2 selectively about either the pivot 4 or the pivot 17 which includes a hydraulic jack 18 having a rod portion 18a which is pivotally connected to the crucible 2 at the location 44 and which may be extended within its associated cylinder 18b to execute the desired tilting movement of the crucible. Since one of the bearings for the pivots 4 and 17 will be closed, the cylinder portion 18b may be centrally located in respect to the crucible and upward extensible movement of the rod portion 18a will cause pivoting of the crucible about whichever of the support beings 19 or 20 is covered by the bearing closing members or locking elements 21 and 22. When the locking members 21 and 22 are closed over the fork-shaped ends of the bearing supports 19 or 20, respectively, the associated pivots 4 or 17 will be locked at the time so that this end of the crucible may not be lifted up. Because the crucible 2 should be tilted only about one of the two pivots at a time, one the pivot bearings 19 or 20 must be locked at all times. For this reason, the locking members 21 and 22 are connected by an assembly of levers and the rod 23 so that one of the locking elements 21 or 22 will always be arranged to cover the associated bearing supports 19 or 20 when the other one uncovers its associated bearing support. The rod 23 is shifted by a control rod member 46 which is slidable in a control cylinder 48.

In the position of rest, as indicated in FIG. 1, a crucible 2 rests with its trunnions 4 and 17 supported in the associated bearings 19 and 20 and the jack 18 is relieved of pressure.

In the embodiment indicated in FIG. 3, there is provided a crucible 2 having trunnions 4' and 17 which rest in associated bearing supports 19' and 20 as in the other embodiment. In this embodiment, locking members 21' and 22 are also associated with the bearings 19' and 20 as in the other embodiment. In this embodiment, a slag bucket 14' is provided with trunnions 14a which are supported on a mounting fixture or bracket 24 which is connected to a furnace frame member 25 rather than to the covering as indicated in FIGS. 1 and 2. The arrangement includes a mounting base or platform portion 26 upon which is pivotally mounted an operators stand 27 on pivots or hinges 29. A hydraulic member 28 which is movable by a suitable control (not shown) is pivotally connected to the platform 27 so that it can be swung upwardly to the dotted line position indicated for access to the top of the slag ladle 14'.

The platform 27 is advantageously provided with an extending arm portion 30 which is connected by a rod 31 to a rod member 23 which is connected between the locking members 21' and 22'. The arrangement is such that when the pivot 17 is locked on its mounting stand 20', the pivot 4 may be uncovered or free from its asso ciated stand 19' only when the platform 27 is raised up to expose the top of the ladle 14'. In this manner, no pouring of metal will take place until the working platform 27 is first positioned in an upright position away from the top of the ladle.

While specific embodiments of the invention have been shown and described in detail to illustrate the application of the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.

What is claimed is:

1. An induction furnace comprising, a crucible having a first end with means adjacent said first end for pouring melt therefrom and a second end opposite from said first end having means adjacent said second end for removing slag therefrom, mounting means for supporting said crucible including a first substantially horizontal pivot means adjacent said first end and a second substantially horizontal pivot means adjacent said second end permitting selective pivotal tilting movement of said crucible about first and second pivots for pouring melt and for removing slag respectively, said first and second pivot means each including a supporting bearing having an opened top and a trunnion defined on said crucible supported in said opened top bearing, and releasable locking means associated with at least one of said bearings for releasably locking at least one of said trunnions in at least one of said bearings.

2. An induction furnace, according to claim 1, wherein said first and second pivots are parallel.

3. An induction furnace, according to claim 1, wherein said means at said first end of said crucible for pouring melt include a lip, said means at said second end of said crucible for removing slag comprising a gutter having an outer end extending outwardly from said crucible, and means for supporting a slag bucket adjacent the outer end of said gutter in a position to receive slag material therefrom when said crucible is pivoted about said second pivot.

4. An induction furnace, according to claim 1, including a covering for said crucible, means holding said covering to said crucible when said crucible is pivoted about said first pivot, and mounting means on said cover for mounting a slag ladle adjacent said second end in a position to receive slag from said crucible.

5. An induction furnace, according to claim 1, wherein said mounting means includes means for pivotally sup porting a ladle for receiving slag adjacent said second end of said crucible.

6. An induction furnace comprising, a crucible having a first end with means adjacent said first end for pouring melt therefrom and a second end opposite from said first end having means adjacent said second end for removing slag therefrom, mounting means for supporting said crucible including a first substantially horizontal pivot means adjacent said first end and a second substantially horizontal pivot means adjacent said second end permitting selective pivotal tilting movement of said crucible about first and second pivots for pouring melt and for removing slag respectively, including a slag ladle, and means for mounting said slag ladle adjacent said second end of said crucible in a position to receive slag therefrom, a supporting wall structure adjacent said slag ladle, an operators platform pivotally mounted on said support wall structure and being movable between a horizontal position at which said platform covers at least a portion of said ladle to a vertical position at which said ladle is uncovered.

7. An induction furnace according to claim 6 wherein said first and second pivot means include first and second bearing members having opened tops and trunnions formed on said crucible adjacent said first and second ends which are releasable engageable in the opened tops of said first and second bearing members respectively, and locking means associated with said first and second bearing members for selectively locking one of said bearing members to hold the associated trunnion therein and to release the other of said trunnions to permit upward tilting movement of one end of said crucible, and control means connected to said locking means and said platform for raising said platform when said second bearing is locked for the removal of slag.

8. An induction furnace, according to claim 1, wherein said mounting means includes upright supporting members adjacent said first and second ends of said crucible, said crucible having a gutter formation adjacent said second end extending outwardly to said second pivot, a cover for said crucible connected to said crucible to be movable with said crucible during tilting movement thereof, and means supporting a ladle below said cover adjacent the outer end of said gutter in a position to receive slag material from said gutter when said ladle is pivoted about said second pivot.

9. An induction furnace, according to claim 1, including means for pivoting said crucible including a rod member slidable in a piston connected to said crucible.

10. An induction furnace comprising, a crucible having a first end with means adjacent said first end for pouring melt therefrom and a second end opposite from said first end having means adjacent said second end for removing slag therefrom, mounting means for supporting said crucible including a first substantially horizontal pivot means adjacent said first end and a second substantially horizontal pivot means adjacent said second end permitting selective pivotal tilting movement of said crucible about first and second pivots for pouring melt and for removing slag respectively, said first and second pivot means including first and second bearing members having opened tops and first and second trunnions formed on said crucible adjacent said first and second ends which are releasably engageable in the opened tops of said first and second bearing members respectively, and locking means associated with said first and second bearing members for selectively locking one of said bearing members to hold the associated trunnion therein and to release the other of said trunnions to permit upward tilting movement of this end of said crucible.

References Cited UNITED STATES PATENTS 3,088,182 5/1963 Tama et al. 26633 3,310,298 3/1967 Huwyler et al. 26633 3,311,361 3/1967 Zeperwick 26636 3,350,083 10/1967 Buhrer et al. 26638 J. SPENCER OVERHOLSER, Primary Examiner R. D. BALDWIN, Assistant Examiner U.S. Cl. X.R. 26638 

